The role of bivalent ions in the regulation of D-loop extension mediated by DMC1 during meiotic recombination
Veronika Altmannova,
Mario Spirek,
Lucija Orlic,
Atis Jēkabsons,
Tereza Clarence,
Adrian Henggeler,
Jarmila Mlcouskova,
Raphaël A.G. Chaleil,
Joao Matos,
Lumir Krejci
Affiliations
Veronika Altmannova
Department of Biology, Masaryk University, Brno 62500, Czech Republic; International Clinical Research Center, St. Anne’s University Hospital, Brno 65691, Czech Republic; Corresponding author
Mario Spirek
Department of Biology, Masaryk University, Brno 62500, Czech Republic; International Clinical Research Center, St. Anne’s University Hospital, Brno 65691, Czech Republic
Lucija Orlic
Max Perutz Labs, University of Vienna, Dr. Bohr-Gasse 9 1030 Vienna, Austria
Atis Jēkabsons
Department of Biology, Masaryk University, Brno 62500, Czech Republic; International Clinical Research Center, St. Anne’s University Hospital, Brno 65691, Czech Republic
Tereza Clarence
Biomolecular Modelling Laboratory, The Francis Crick Institute, London, UK
Adrian Henggeler
Max Perutz Labs, University of Vienna, Dr. Bohr-Gasse 9 1030 Vienna, Austria
Jarmila Mlcouskova
International Clinical Research Center, St. Anne’s University Hospital, Brno 65691, Czech Republic
Raphaël A.G. Chaleil
Biomolecular Modelling Laboratory, The Francis Crick Institute, London, UK
Joao Matos
Max Perutz Labs, University of Vienna, Dr. Bohr-Gasse 9 1030 Vienna, Austria
Lumir Krejci
Department of Biology, Masaryk University, Brno 62500, Czech Republic; International Clinical Research Center, St. Anne’s University Hospital, Brno 65691, Czech Republic; National Center for Biomolecular Research, Masaryk University, Brno 62500, Czech Republic; Corresponding author
Summary: During meiosis, programmed DNA double-strand breaks (DSBs) are repaired by homologous recombination. DMC1, a conserved recombinase, plays a central role in this process. DMC1 promotes DNA strand exchange between homologous chromosomes, thus creating the physical linkage between them. Its function is regulated not only by several accessory proteins but also by bivalent ions. Here, we show that whereas calcium ions in the presence of ATP cause a conformational change within DMC1, stimulating its DNA binding and D-loop formation, they inhibit the extension of the invading strand within the D-loop. Based on structural studies, we have generated mutants of two highly conserved amino acids – E162 and D317 – in human DMC1, which are deficient in calcium regulation. In vivo studies of their yeast homologues further showed that they exhibit severe defects in meiosis, thus emphasizing the importance of calcium ions in the regulation of DMC1 function and meiotic recombination.
